Pouring on the Garden

 Pouring the leftover pickle vinegar onto a dandelion

I get through a lot of pickles, onions and gherkins mainly. I’m sure you are not really interested in my supper routine but I do find them very palatable with a bit of cheese. 

The Americans seem to love pickles too if the raised bed Facebook page is anything to go by.  Nearly every other post is someone taking pictures of their ‘canning’ harvest and cucumbers seem to be top of the list.  I have pickled my own onions and beetroot in the past and probably will do again, but I’ll need to set a field aside for the amount I get through. I find the vinegar really settles the stomach and medicinal, curing anything from sunburn to hiccups. It’s not much of a breath freshener though and I do see people backing away from me when I’m talking sometimes, but maybe that’s more to do with what I’m saying rather than what I am spraying if you get me.

Natural Weedkiller

There are also a lot of posts on the Facebook page about how vinegar makes a great weed killer. It’s claimed to be as effective as the harsh polluting chemicals we get from the multinationals. The recipe is nearly always a subtle modification of:  ½ gallon of vinegar, ½ cup of salt and 2 tablespoons of washing up liquid. I hasten to point out that all of these items are still chemicals, even though we use them so often we forget. Vinegar contains acetic acid, salt is sodium chloride and washing up liquid is made in an industrial process, this is used to spread out the water droplets when it’s applied to the plants. It’s more commonly known as a “surfactant”

I thought it was about time I did my own research and do some tests myself, so over the last year or so I have been trying it out on my own garden and taking into account the fact these are still chemicals I have been careful where I pour it.

My driveway has a lot of cracks in it so the solution was poured into the areas where perennial and annual weeds were growing. The combination of the acetic acid, salt, and soap eventually killed many annual weeds, especially when applied to small weeds, but the perennials just kept coming back.

The vinegar - salt solution works on contact primarily by disrupting the cell walls of the leaves. It will not travel long distances through the plant (say, from one leaf to another). So if you don’t get complete coverage of the plant leaves with the vinegar and salt solution, there is potential for the plant to re-grow from the living tissues. The vinegar- salt solution, since it doesn’t move throughout the plant, will not be effective on perennial weeds. It will burn off the top growth of perennials (which may be desirable), but it will not provide long-term control.

The contact nature of the vinegar and soap can be a benefit, though. If you need to kill weeds in close proximity to a desirable plant for example.  But you will need to miss out the salt or you will poison the soil and it could run off into the waterways.

I have also been emptying the salt free contents of my amassed vinegar bottles directly onto weeds again with mixed results. Some annual weeds have withered but the perennial dandelions have just got mottled leaves and are still growing well. I also have small heaps of red pepper bits and dill leaves collecting in corners where they came out of the gherkin jars. 

Industrial

For vinegar to be really effective we would need industrial strength. Shop bought vinegar is about 2-5% acetic acid and for a weedkiller, it’d need to be about 20% acid. If that were the case we would have to adorn rubber gloves, facemasks and protective clothing and not the pinny I usually wear.

So all in all, vinegar does do a bit on the garden, but I’d be tempted to apply it without the salt as it’ll poison the ground and wash into the waterways and soap… so it’s straight out of the jars from now on.

Another idea

As things are being throw into the garden from the kitchen, how about pouring the cooking water from vegetables onto the plants (after it’s cooled of course) again, it’d need to be a solution with no salt added.

Vitamins and minerals lost from cooking the vegetables are released in the water.  Even boiled egg water leaves behind calcium, so use the liquid to water calcium-loving solanaceous garden plants: tomatoes, potatoes, aubergine, peppers, and squash.

Even pasta and potato starch water will spur the release of plant nutrients in the soil, meaning starch may be better for plants than for us.